Yeah, I've seen this in other groups as well. They (spammers) are
getting very clever. Very short posts with legit content and then the
link is using URL shorterning services like this one.
Hopefully, google will pick up on this and start to dereference short
urls and perhaps from that see that its spam.
-Isak
Groups spam fighting has got a lot better lately, but there's still a
long way to go and we know it. Working on it ....